Susan Sarandon dominates "Lorenzo's Oil" as the ultimate nurturing mother out to save her child. But in this case, it's a seemingly futile rescue effort, since the child is under attack by an unseen and virtually unknown enemy, a disease that is too rare and too new to adequately comprehend, and therefore not very high on the priority list of medical investigation.

Sarandon is fearless in her performance, not at all afraid to make her character appear so single-minded that she is often curt and occasionally downright obnoxious. It's a wide-ranging role, played to the hilt, and Sarandon would seem to be a sure-thing in the coming Oscar race. (Not only will Sarandon be nominated as best actress, I'm guessing she will win.)

"Lorenzo's Oil" is a true story, a case study of parental love as Augusto and Michaela Odone (Nick Nolte and Sarandon) refuse to roll over and let their child suffer without a fight.

The film begins in 1983 as 5-year-old Lorenzo (Zack O'Malley Greenburg) is initially misdiagnosed. But as time passes, his parents become certain that the boy's wild mood swings and the sudden development of self-destructive habits are due to an illness the doctors simply cannot pinpoint.

The disease is eventually identified as adrenoleukodystrophy, referred to as ALD, which is inherited by young boys from their mothers, who are merely carriers, and causes gradual degeneration until the patient dies, usually within two years of being diagnosed.

The Odones enlist the aid of a well-intentioned but ineffectual doctor (Peter Ustinov) who specializes in ALD. But they soon become frustrated with his hesitant approach, though they allow Lorenzo to become involved in experimental treatment. It isn't long, however, before the Odones relinquish their passive approach for a more aggressive tack.

Augusto begins spending hours in libraries, poring over medical journals, looking for anything that might hint at a cure. Meanwhile, Michaela spends every waking moment tending to her deteriorating child's needs, fighting off guilt at having been the carrier of this dreaded disease.

They find themselves battling both doctors and other parents of ALD children as they pursue their goal, and after some years they do begin to make some progress. They help develop a compound, the title oil, that will stave off some symptoms and point toward hope for the future. Ultimately, the ending cannot be a "happy" once, but it is certainly filled with optimism.

Directed and co-written by Australian George Miller (the "Mad Max" films, "The Witches of Eastwick"), who is a medical doctor as well as a filmmaker, "Lorenzo's Oil" is meticulous storytelling, evenly paced and filled with detail. There is also a depth of character here and an intelligence that are missing from disease-of-the-week television movies that tackle subjects like this.

The performances are all first-rate, including the six children (led by young Greenburg) who play Lorenzo at various stages of his life. Nolte's affected Italian accent takes some getting used to, but the film is so involving and his performance so compelling that after awhile it doesn't really matter. And it's very nice to see Ustinov again after too long an absence from the big screen.

The real knockout here, however, is Sarandon, who is absolutely riveting. She's every bit as wrenching, touching and fulfilling as the film itself. And that's saying something.

"Lorenzo's Oil" is rated PG-13 for some language, though it is obviously too intense for young children.